. >>> world leaders, include vice president joe biden are gathering in rome ahead of the installation of pope francis. let's get to keer simmons. >> reporter: good morning. even if it is raining like this tomorrow, this area will still be packed as you say. world leaders are flying in. the pope meeting with the argentina president. the pope's message, remember the poor, and his style is winning fans for people on the street. as pope francis prepares for the installation mass, vice president biden arrived in rome sunday. it is ordinary men and women that are connecting with the pope in an extraordinary way. francis walking over to a crowd of a few hundred people just to say hello, leaving his security scrambling. then sunday, he greeted tens of thousands in st. peter's square for his first angeles, even making the mass. in the crowd, we met philadelphia's cardinal. >> this is unique. this is a wonderful opportunity. i mean, it is the first time the new pope, pope francis appeared, first time he gives his blessing here. >> reporter: preparations in the same square are under way. we have